System Integrity Protection (SIP) on macOS

Overview

System Integrity Protection (SIP), also known as “rootless,” is a macOS security feature that restricts the root user account and limits what actions can be performed on protected parts of the operating system. Even with sudo, processes cannot modify system files, load unsigned kernel extensions, or tamper with protected system processes. For Mac admins, SIP is a foundational security layer that shapes how you deploy tools, manage configurations, and troubleshoot systems.

History

SIP was introduced in OS X El Capitan (10.11) in 2015. Before SIP, any process running as root had unrestricted access to the entire file system and could modify system binaries, frameworks, and configuration files. This made macOS vulnerable to rootkits and other persistent malware that could embed itself in the operating system. SIP fundamentally changed the macOS security model by introducing kernel-level enforcement that even root cannot bypass while the system is running normally.

What SIP Protects

SIP enforces restrictions across several domains:

Protected File System Locations

The following directories are protected by SIP and cannot be modified by any process, including root:

Note: /usr/local is explicitly excluded from SIP protection, which is why package managers like Homebrew install to this location.

Runtime Protections

Beyond the file system, SIP also enforces:

• Process restrictions – Debugging and code injection into system processes is blocked, even with root or task_for_pid()
• Kernel extension restrictions – Unsigned or improperly signed kexts cannot be loaded
• NVRAM protection – Certain NVRAM variables critical to boot security cannot be modified from userland
• dtrace restrictions – System processes cannot be inspected with dtrace unless SIP is partially disabled

How SIP Works

SIP is enforced at the kernel level, not in userland. The restrictions are set before the system boots into the normal operating environment, which means no running process – regardless of privilege level – can disable SIP. The configuration is stored in NVRAM and can only be modified from macOS Recovery.

Checking SIP Status

# Check current SIP status
csrutil status

A fully enabled SIP will report:

System Integrity Protection status: enabled.

On systems where SIP has been partially modified, you may see individual flags listed:

# Detailed SIP configuration (on systems with partial SIP)
csrutil status --verbose

Signed System Volume (SSV)

Starting with macOS Big Sur (11.0), Apple extended the SIP concept with the Signed System Volume (SSV). The entire system volume is cryptographically sealed with a tree of SHA-256 hashes. Any modification to any file on the system volume invalidates the seal, and macOS will refuse to boot from a tampered volume.

SSV makes it impossible to modify system files even with SIP disabled – the volume’s cryptographic seal would be broken. This is a significant shift from earlier macOS versions where disabling SIP granted full access to system files.

# Verify the system volume's cryptographic seal
csrutil authenticated-root status

Disabling SIP (and Why You Should Not)

SIP can only be disabled from macOS Recovery:

1. Restart your Mac and boot into Recovery Mode (hold Command+R on Intel, or hold the power button on Apple Silicon)
2. Open Terminal from the Utilities menu
3. Run:

# Disable SIP entirely (from Recovery only)
csrutil disable

# Disable specific SIP protections only
csrutil enable --without kext --without dtrace

4. Restart the Mac

Warning: Disabling SIP removes a critical security boundary. Any malware running as root can now modify system files, inject code into system processes, and persist across reboots. Only disable SIP for specific debugging or development tasks, and re-enable it immediately after.

Re-enable with:

# Re-enable SIP (from Recovery only)
csrutil enable

Impact on Mac Admin Tools

SIP has significant implications for Mac administration:

• No modifying system binaries – You cannot replace or patch system tools
• No custom LaunchDaemons in /System – Place them in /Library/LaunchDaemons/ instead
• Kernel extensions require approval – Unsigned kexts are blocked; even signed kexts need user or MDM approval
• Some legacy tools break – Older admin tools that relied on modifying /usr/bin or hooking into system processes may not function with SIP enabled
• MDM can manage SIP – On supervised devices, MDM profiles can be used to configure SIP settings without requiring manual Recovery boot

Paths Admins Should Use Instead

MDM and SIP Management

On MDM-supervised devices, certain SIP-related behaviors can be managed through configuration profiles:

• Kernel extension allow lists – Approve specific kexts by Team ID without disabling SIP
• System Extension policies – Manage the newer System Extensions framework (which replaces kexts and works within SIP)
• Secure Boot policy – On Apple Silicon, MDM can influence boot security settings

Key Takeaways

SIP is non-negotiable for production Mac fleets. Any tool or workflow that requires SIP to be disabled should be treated as a legacy dependency and migrated to SIP-compatible alternatives. With Signed System Volume on Big Sur and later, even disabling SIP no longer grants the access it once did. Build your management workflows around SIP, not against it.